Turbomachines, including steam turbine power systems (also referred to as steam turbines or steam turbomachines), are employed in thermal power plants and may also be utilized in a combined-cycle configuration whereby steam is preheated prior to entering the turbine. A combined-cycle configuration includes a gas turbine and a heat recovery steam generator (HRSG), which utilizes exhaust from the gas turbine to generate steam for subsequent use in the steam turbine. When starting a steam turbine, e.g., from a cold or relatively cold state, it is desirable to heat the thick-walled components of the steam turbine to operational temperatures. During this time, the steam generating components (e.g., boiler, gas turbine and HRSG) are typically run at a sub-design level load so as to provide lower-temperature steam (relative to operating temperature steam) to the steam turbine, thereby limiting the temperature difference (and with it, the thermal expansion stresses) within the turbine components. Running higher-temperature steam through the steam turbine at the start-up phase can shorten the usable life of its components or can damage the turbine, e.g., by fracture initialization or plastic deformation. However, operating the steam generator at lower loads can waste fuel due to its lower efficiency, and the corresponding lower efficiency of the steam turbine. Furthermore, operating at these lower loads can yield higher emission levels due to less complete combustion.